Delivery device for use with bag-making machines



March 24, 1970 A. FINKE 3,502,006

DELIVERY DEVICE FOR USE WITH BAG-MAKING MACHINES Filed March 18. 1968 INVENTOR Arno FlNKE his ATTORNEYS United States Patent Int. Cl. B65h 3 3/00, 29/68 US. Cl. 93-93 5 Claims ABSTRACT OF THE DISCLOSURE In a delivery device for use with bag-making machines for making paper or plastics materials bags, the bags made by the bag-making machine are deposited in a vertical position on a delivery table by means of a delivery cylinder, which is provided with grippers, and are combined in stacks on the delivery table. The delivery cylinder is preceded by means for collecting and superimposing two or more bags and for decelerating the resulting sets of bags. The output speed of the bag-making machine is selected to correspond to the product of the peripheral speed of the delivery cylinder and the number of bags in each set of bags.

This invention relates to a delivery device for use with bag-making machines for making paper or plastics materials bags, in which device the bags made by the bag-making machine are deposited in a vertical position as a delivery table by means of a delivery cylinder, which is provided with grippers, and are combined in stacks on the delivery table. In known delivery devices of thi kind (see German Patent Specification No. 617,588), the flexible workpieces which are moved at the full speed of travel are suddenly decelerated to zero as they impinge on the delivery table. The stack of upright bags grows in a horizontal direction and pushes ahead of itself a supporting bracket, which rests on the delivery table and consists, as a rule, of wood.

It has now been found that such a delivery device for bags will not permit of a desirable increase in the speed of the machine, particularly with relatively long bags. The kinetic energy of the bags increases with an increase in the machine speed and upon the sudden deceleration of the bags from the speed of travel to zero speed results in a deviation of the bags from their upright position on the delivery table. The bags are upset or collapse under the force of the impact and can no longer be gathered in a neat stack in a satisfactory condition.

It is an object of the inventon to eliminate this disadvantage and to provide a bag-delivering device which enables both a satisfactory delivery even of very long bags and a previously unattained increase of the speed of the bag-making machine.

To accomplish this object, it is proposed according to the invention to provide a delivery device of the kind mentioned first hereinbefore with means for collecting and superimposing two or more bags and for decelerating the resulting sets of bags before the delivery cylinder and to select such an output speed of the bag-making machine that said speed corresponds to the product of the tangential velocity of the delivery cylinder and the number of bags in each set of bags. Intervals are thus formed between the operations whereby bags are transferred to the delivery cylinder because every other bag is removed from the path of travel and deposited on the next successive bag or this operation is repeated several times and only the resulting set of two or more bags is transferred to ice the delivery cylinder. The speed of the latter may then be reduced to correspond to the quotient of the output speed of the bag-making machine divided by the number of bags which are collected.

The sets of bags are suitably formed by a gripper cylinder, which is tangential to the path of travel of the bags and performs one revolution per cycle of the bagmaking machine, the gripping device of said gripper cylinder being controlled so that the operations of gripping and entraining a bag or set of bags and depositing it on the next bag arriving during the revolution are performed once or repeatedly.

In a development of the invention, the deceleration may be effected in that the sets of bags are received behind the collecting device by conveyor belts which revolve at the output speed of the bag-making machine and over and under the plane of travel, at least one fixed braking strip having an inclined run-up surface rising in the direction of travel beyond the level of the belts is provided between the lower belts, and the upper belts are upwardly deflected at a point which is adjacent to the braking strip or strips. It will be particularly desirable if the point where the upper belts are deflected is adjustable parallel to the direction of travel so that the point where the upper belts are lifted from the workpieces can be adjusted as required, particularly in view of the required deceleration.

According to a further proposal of the invention, stop fingers which rotate about a stationary axi may be provided at the point where the delivery cylinder receives the sets of bags and said fingers may be staggered relative to the grippers of the delivery cylinder and arranged to enter into grooves of the delivery cylinder during the rotation of said fingers. In this manner, a satisfactory receipt of the sets of bags by the grippers of the delivery cylinder can be ensured because the stop fingers reliably prevent an excessive movement of the bags into the angle between the peripheral surface of the delivery cylinder and its grippers and damage to such bags by the closing grippers. The rotating stop fingers constitute movable stops, which determine the position of the sets of bags immediately before the transfer to the delivery cylinder and which may efiect a final deceleration of said sets of bags.

The invention will be described hereinafter with reference to an embodiment shown by example on the drawing, in which:

FIG. 1 is a diagrammatic side elevation showing a bagdelivering device according to the invention, and

FIG. 2 is a sectional view taken on line IIII in FIG. 1.

The finished bags leave the bag-making machine on a path of travel having the orientation and direction indicated by the arrow 1. Of the conveying means used for this purpose, only the upper belts 2 and their forward reversing pulleys 3 are shown in a broken-away representation. The upper belts cooperate in their illustrated portion with lower belts 4a-d, which extend around sets of reversing pulleys 5-7. One of said sets of reversing pulleys 5-7 is driven so that the belts 4 have the same speed as the belts 2 and the bags leaving the bag-making machine.

The reversing pulleys 3 for the upper belts 2 are immediately succeeded by a gripper cylinder 8, which is rotatably mounted above the belts 4 and provided with a set of grippers 9. The gripper cylinder 8 performs one revolution per cycle of the bag-making machine at a tangential velocity which is equal to the speed of travel. The set of grippers 9 of the gripper cylinder 8 are controlled to grip, e.g., every other bag at its leading edge and to deposit said bag on the next arriving bag after one revolution so that sets of two bags are formed.

Sets of more than two bags can also be formed if the set of grippers 9 are controlled to grip the initially formed set of two bags and to deposit said set on the.

next succeeding bag and so forth until the desired number of sets are collected in the set. The set of grippers are then controlled to perform anempty revolution. Every other revolution will be an empty revolution when sets of two bags are to be formed.

Such control means can be provided by a person skilled in the art in various forms, known per se. A preferred example of such control means comprises an additional cam, which is pivotally movable with the desired timing into and out of its operative position and which initiates an empty revolution by delaying the closing of the set of grippers so that they do not grip a bag.

The bag or bags which are revolved by the gripper cylinder 8 are held on the cylinder against the action of centrifugal force by belts 25, which extend around the cylinder so that the bags will be reliably controlled also when the grippers have opened in time and the bags cannot fall down or slip out of position and will be deposited on the next succeeding workpiece in registry therewith.

Those bags which have been superimposed are forwarded in the present example to braking strips 27a-c by the lower belts 4a-d in cooperation with additional upper belts 26a, b. The upper belts 26 extend around sets of guide pulleys 28-30. The pulleys of one of said sets are driven. The set of guide pulleys 29 are on a higher level so that the belts 26 are diverted in their lower course from the belts 4 in the direction of travel. Holding-down pulleys 31 may be shifted in their mounting in the directions which are indicated by the double arrow 32 and can be fixed in said mounting. With the holding-down pulleys 31, the point where the upper belts 26 lift from the workpieces can be adjusted as desired. As is particularly apparent from FIG. 2, the braking strips 27 are disposed between the belts 4 and extend a certain distance beyond the same. Inclined run-up surfaces 33 cause the arriving pairs of bags to slide onto the braking strips so that said bags are decelerated owing to the friction on the braking strips and the cessation of the driving action of the lower belts 4. The holding-down pulleys 31 can be adjusted to maintain the driving action of the upper belts 26 for such a portion of the length of the braking strips as is required to move the pairs of bags at the desired reduced speed under the grippers 34 of the delivery cylinder 35.

Because the pairs of bags must not move to a large extent into the angle between the grippers 34 and the periphery of the delivery cylinder 35 as the bags would then be damaged by the closing grippers, rotating stop fingers 36 are provided, which are staggered with respect to the plurality of grippers 34 spaced one beside the other and enter grooves of the delivery cylinder 35. The

velocity of the stop fingers is the same as the tangential velocity of the delivery cylinder so that the pairs of bags can be gripped by the grippers 34 accurately and without disturbance and damage and are thus received by the delivery cylinder 35 and subsequently deposited on a delivery table 37 in the manner known for individual bags and are held on said table in an upright position by a slidable bracket 38.

The transmission ratio between the stop fingers 36 and the delivery cylinder 35 must be selected so that the number of revolutions of the stop fingers 36 during a revolution of the delivery cylinder is divisible by the number of gripper stations 34 so that the stop fingers cooperate in the same manner with each of the sets of grippers 34.

When two bags are deposited at a time, this can be effected at one half of the rate at which single bags are deposited and the deposition rate. may be further decreased in inverse proportion if more bags are collected in each set so that the speed of the bag-making machine can be increased twice or several times before the deposition rate is reached which is permissible for single bags.

What is claimed is:

1. A delivery device for use with bag-making machines for making paper or plastics materials bags, in which device the bags made by the bag-making machine are deposited in a vertical position on a delivery table by means of a delivery cylinder, which is provided with grippers, and are combined in stacks on the delivery table, characterized in that the delivery cylinder is preceded by means for collecting and superimposing two or more bags and for decelerating the resulting sets of bags and the output speed of the bag-making machine is selected to correspond to the product of the tangential velocity of the delivery cylinder and the number of bags in each set of bags.

2. A delivery device according to claim 1, characterized in that a gripper cylinder which is tangential to the path of travel of the bags and performs one revolution per cycle of the bag-making machine is provided to form the sets of bags, and the gripping device of said gripper cylinder is controlled so that the operations of gripping and entraining a bag or set of bags and depositing it on the next bag arriving during the revolution are performed once or repeatedly.

3. A delivery device according to claim 1, characterized in that the sets of bags are received behind the collecting device by conveyor belts which revolve at the output speed of the bag-making machine and over and under the plane of travel, at least one fixed braking strip having an inclined run-up surface rising in the direction of travel beyond the level of the belts is provided between the lower belts, and the upper belts are upwardly deflected at a point which is adjacent to the braking strip or strips.

4. A delivery device according to claim 3, characterized in that the point where the upper belts are deflected is adjustable parallel to the direction of travel.

5. A delivery device according to claim 1, characterized in that stop fingers which rotate about a stationary axis are provided at the point where the delivery cylinder receives the sets of bags and said fingers are staggered relative to the grippers of the delivery cylinder and arranged to enter into grooves of the delivery cylinder during the rotation of said fingers.

References Cited UNITED STATES PATENTS 1,961,724 6/1934 Zenke.

2,856,189 l0/l958 Winkler 27169 2,872,190 2/1959 French.

3,019,886 2/1962 Winkler.

3,075,678 l/l963 Huck.

3,172,342 3/1965 Potdevin.

3,323,425 6/1967 Brockmuller.

3,404,609 10/1968 Hartbauer 93-93 FOREIGN PATENTS 1,087,853 10/1967 Great Britain.

WAYNE A. MORSE, JR., Primary Examiner U.S. Cl. X.R. 271-69 

